Known digital tuning systems, such as disclosed, for example, in "Radio Mentor Electronic" 1978, No. 4, pages 136-138, make it possible to tune a receiver by feeding in the digits of a receiving frequency or transferring a stored number representing the receiving frequency into the tuning system and to effect quasi-continuous tuning by the input of pulses which are counted in a counter forming part of the tuning system. The tuning process is controlled in dependence upon the counter position, or count state. In the tuning system disclosed in the above-mentioned publication, such continuous tuning with pulses is provided for manual tuning as well as for station search operation.
In such a tuning system, manual tuning may be effected, for example, in that starting with the existing tuning position, the receiving frequency is changed upwardly or downwardly depending on the direction of rotation of a manual tuning knob which generates the pulses.
There then exists the problem in such manual, continuous tuning, when changing from one tuning range to another, that a receiving frequency may be set which lies outside the receiving frequency range. In the known tuning system, such a situation is handled by causing a frequency indicator to emit a visual blinking signal. By calling up a stored station or puting in a receiving frequency, a frequency can be set within the tuning range and continuous tuning can then be effected from that frequency.